Patches vs. Thumbnail



Due to an earlier thread, an inner tube arrived today from Jobst:

http://groups.google.com/group/rec.bicycles.tech/msg/ebb1cf0e0890033a

Jobst's presta-valve Taiwan inner tube sported 11 intriguing patches.

Three of Jobst's patches were miniature Rema patches, about the size
of the end of my little finger. I never saw such things before and
have no idea where to get them.

Two of Jobst's patches were round and normal-size--except that their
edges were green instead of red!

I muttered, "I do not like green eggs and . . ."

(Bonus points to anyone who can name the Reginald Hill Dalziel and
Pascoe novel that opens with an even more ominous take on green all
over things.)

Jobst's other six patches were normal round red-edged Rema patches.

Except that the red edges were serrated or lobed, like little
sunbursts, not round like my Rema patches. Most likely, older Rema
patches had scalloped edges, while modern ones are perfect circles
with smooth edges.

(As anyone who peels things knows, serrated edges are much harder to
remove cleanly. After you peel the little pointy part back, your
victim tends to tear and rip, down in the indentation.)

Minor observations:

1) The edges of Jobst's patches look a lot better than mine. It's hard
to describe, but it kinda-sorta looks like more glue.

2) Jobst may get more pinch flats than I do. Six of the eleven patches
were paired, with two of them actually touching.

3) Boy, those are big holes! I'm used to the nearly invisible holes
left by needle-pointed goathead thorns that can't be seen after you
scrape or sand a tube and spread glue on it.

I started with Jobst's three mini-patches. Two came off, but I judged
that they were noticeably more stubborn than my big smooth-edged Rema
patches.

Jobst's third mini-patch was much harder to peel, but it tore off when
pulled hard. "Tore" is the right word, because it left a scar on the
inner tube.

So Jobst's little round patches did come off, but they stuck better
than my big patches.

The two smooth-edged round green patches came next. They came off
about as easily as my red Rema patches, maybe a bit easier. I'd call
those two a draw.

That left Jobst's six big red serrated-edge Rema patches.

Two of them came off markedly easier than my patches and with
noticeably less black from the tube.

But four of Jobst's big Rema patches are unquestionably better than
mine--they're still on his inner tube. I could raise their edges, but
they just don't peel.

Jobst's secret might be smooth sanding instead of rough scraping . . .

A thicker or thinner layer of glue . . .

A longer or shorter drying time . . .

A better batch of glue . . .

Or even serrated instead of smooth edge Rema patches . . .

Anyway, here's a picture of Jobst's tube with the white powder around
the puncture, matching the white powder mark on the green patch:

http://i9.tinypic.com/4hixlpv.jpg

Left-click on the lower right in Explorer for full-size.

The 7 patches above the spoke were peeled off Jobst's tube.

The 3 mini patches were harder to peel off than my patches (and are
very black).

The 2 green patches peeled off about as easily as my patches (little
black, mostly green glue).

The 2 big Rema patches peeled off easily (almost no black on one).

But 4 of Jobst's big red Rema patches didn't peel off at all, so I say
that he wins. Maybe heat would help, but a naked thumbnail just gouges
the edges.

The 5 patches below the spoke were peeled off my tubes in the old
thread. I should emphasize that all the patches came off very, very
reluctantly and would have all held air just fine.

Cheers,

Carl Fogel
 
Carl Fogel writes:

> Due to an earlier thread, an inner tube arrived today from Jobst:


>

http://groups.google.com/group/rec.bicycles.tech/msg/ebb1cf0e0890033a

> Jobst's Presta-valve Taiwan inner tube sported 11 intriguing

patches.

> Three of Jobst's patches were miniature Rema patches, about the size
> of the end of my little finger. I never saw such things before and
> have no idea where to get them.


> Two of Jobst's patches were round and normal-size--except that their
> edges were green instead of red!


> I muttered, "I do not like green eggs and . . ."


> (Bonus points to anyone who can name the Reginald Hill Dalziel and
> Pascoe novel that opens with an even more ominous take on green all
> over things.)


> Jobst's other six patches were normal round red-edged Rema patches.


> Except that the red edges were serrated or lobed, like little
> sunbursts, not round like my Rema patches. Most likely, older Rema
> patches had scalloped edges, while modern ones are perfect circles
> with smooth edges.


> (As anyone who peels things knows, serrated edges are much harder to
> remove cleanly. After you peel the little pointy part back, your
> victim tends to tear and rip, down in the indentation.)


> Minor observations:


> 1) The edges of Jobst's patches look a lot better than mine. It's
> hard to describe, but it kinda-sorta looks like more glue.


> 2) Jobst may get more pinch flats than I do. Six of the eleven
> patches were paired, with two of them actually touching.


> 3) Boy, those are big holes! I'm used to the nearly invisible holes
> left by needle-pointed goathead thorns that can't be seen after you
> scrape or sand a tube and spread glue on it.


> I started with Jobst's three mini-patches. Two came off, but I
> judged that they were noticeably more stubborn than my big
> smooth-edged Rema patches.


> Jobst's third mini-patch was much harder to peel, but it tore off
> when pulled hard. "Tore" is the right word, because it left a scar
> on the inner tube.


> So Jobst's little round patches did come off, but they stuck better
> than my big patches.


> The two smooth-edged round green patches came next. They came off
> about as easily as my red Rema patches, maybe a bit easier. I'd call
> those two a draw.


> That left Jobst's six big red serrated-edge Rema patches.


> Two of them came off markedly easier than my patches and with
> noticeably less black from the tube.


> But four of Jobst's big Rema patches are unquestionably better than
> mine--they're still on his inner tube. I could raise their edges,
> but they just don't peel.


> Jobst's secret might be smooth sanding instead of rough scraping

.. . .

> A thicker or thinner layer of glue . . .


> A longer or shorter drying time . . .


> A better batch of glue . . .


> Or even serrated instead of smooth edge Rema patches . . .


> Anyway, here's a picture of Jobst's tube with the white powder
> around the puncture, matching the white powder mark on the green
> patch:


> http://i9.tinypic.com/4hixlpv.jpg


> Left-click on the lower right in Explorer for full-size.


> The 7 patches above the spoke were peeled off Jobst's tube.


> The 3 mini patches were harder to peel off than my patches (and are
> very black).


> The 2 green patches peeled off about as easily as my patches (little
> black, mostly green glue).


> The 2 big Rema patches peeled off easily (almost no black on one).


> But 4 of Jobst's big red Rema patches didn't peel off at all, so I
> say that he wins. Maybe heat would help, but a naked thumbnail just
> gouges the edges.


> The 5 patches below the spoke were peeled off my tubes in the old
> thread. I should emphasize that all the patches came off very, very
> reluctantly and would have all held air just fine.


The talcum powder on the patch is the small version of patch lift off
that I described in the FAQ. If the tube is not sanded to a matte
finish (by removing the skin containing mold release), lift-off often
progresses to the edge of the patch.

The on-the-road patches were not photographed, but they were all hunch
backed from creep, the ones with talcum on them. I hope you saved the
valve stem because it can be reused if you happen to get a stem
separation as this tube had. There still are such tubes in service.
My friend had on separate at the beginning of our New Idria ride on
Tuesday, 03 Apr. (see rec.bicycle.rides)

Jobst Brandt